There are several kinds of boards to break with this object, they unlock in this order:

Foam board

Balsa Wood board

Oak board

Thin Stone board

Space Rock block

Once Sims complete the Timber Terminator challenge they will often make an uncut gem when they break Space Rock blocks. Since Rainbow Gems, Soulpeace stones, and Tiberium come up frequently, this can be very profitable. Not only that, this also is a reliable (if the player is willing to give enough time for the Sim, or use multiple Sims) way to obtain the Pink Diamond, one of the necessary ingredients of a Simbot.